Neurostimulation therapy is frequently associated with patients having a wide variety of diseases and disorders. In general, neurostimulation therapy works by applying an electrical current to the nerves which may be causing symptoms, such as chronic pain.
In neuromodulation systems, such as spinal cord stimulation systems (“SCS”), a thin wire or lead with electrodes at its distal end is implanted into a patient in the location to be treated, such as within the epidural space of the patient to deliver the electrical pulses to the spinal neural tissue. A pulse generator is typically implanted within a subcutaneous pocket within the patient and is electrically connected to the proximal end of the electrical lead. The pulse generator generates electrical pulses or current which stimulates the nerves around the electrodes at the treatment location.
Leads may be either paddle style or percutaneous. Paddle style leads have a relatively flat wide portion at the distal end of the lead. Flat electrodes are typically positioned on one face of the paddle leads. Percutaneous leads use cylindrical electrodes and are smaller, catheter style leads that are implanted with the aid of a special needle.
The efficacy of the electrical stimulation in facilitating the management of pain of the patient depends upon applying the electrical pulses to the appropriate neural tissue. If the leads migrate, the effectiveness of the electrical stimulation is greatly reduced.
Convention methods for affixing stimulation leads in place include suture sleeves having elastomeric gripping portions positioned around the lead. The suture sleeves are designed to be sutured in place, which in turn “anchors” or positions the lead within the patient. However, some leads are designed to stretch longitudinally as the patient moves. This longitudinal stretching reduces the diameter of the leads. A reduction in the diameter of the leads translates to less gripping by a conventional sleeve. Accordingly, it is desired to retain the stimulation lead at a relatively fixed position over time even if the diameter of the lead changes due to the movement of the patient.